Straight bar knitting machines

ABSTRACT

STRAIGHT BAR KNITTING MACHINE DRAW MECHANISM IN WHICH A MAIN DRAW MECHANISM WITH A SMALLER THAN USUAL DRAW CAM AND INCLUDING AN AUXILIARY DRAW LEVER ADJUSTABLE THROUGH CONNECTIONS TO SELVEDGE STOP ADJUSTABLE LEAD SCREW MECHANSIM, IS CONNECTED TO A THREAD CARRIER DRIVE BAR, AND AN ADDITIONAL DRAW MECHANISM COMPRISES AN ADDITIONAL DRAW CAM DRIVE WITH THE MAIN DRAW CAM, A CAM FOLLOWER LEVER, AND MEANS CONNECTING THE LATTER TO AN ADDITIONAL DRAW LEVER WHICH IS PIVOTALLY MOUNTED ON THE MAIN DRAW LEVER, AND WHEREIN THE ADDITIONAL DRAW LEVER IS CONNECTED TO A SLURCAM DRIVE BAR, SO THAT ACCELERATION AND DECELERATION OF THE THREAD CARRIERS AND SLURCOCKS ARE GOVERNED BY RESPECTIVE DRAW CAMS OF A COMPOSITE DRAW MECHANISM.

Nov. 30, 1971 R BLOOD ETAL STRAIGHT BAR KNITTING MACHINES 5 Sheets-Sheet 1 Filed Feb. 5, 1971) 2; 3 Q Q a h g T Nav. 30, 1971 R BLQQD ET AL STRAIGHT BAR KNITTING MACHINES 5 Sheets-Sheec 2 Filed Feb. 3, 19W.)

Nov. 30, 1971 BLOOD ET AL STRAIGHT BAR KNITTING MACHINES 5 Sheets-Sheet :5

Filed Feb. 5. 19?!) NOV. 30, 1971 BLOOD EI'AL STRAIGHT BAR KNITTING MACHINES 5 Sheets-Sheet 4.

Filed Feb. 5, 1970 Nov. 30, 1971 R. BLOOD ETAL 3,623,342

STRAIGHT BAR KNITTING MACHINES Filed Feb. 5, 191 5 Sheets-Sheet 8 United States Patent G 3,623,342 STRAIGHT BAR KNITTING MACHINES Raymond Blood, Shepshed, Longhborough, and Norman Henry Small, Leicester, England, assignors to William Cotton Limited Filed Feb. 3, 1970, Ser. No. 8,170 Claims priority, application Great Britain, Feb. 12, 1969, 7,481/69 Int. Cl. DIM-b /64 US. Cl. 66-126 8 Claims ABSTRACT GF THE DISCLOSURE Straight bar knitting machine draw mechanism in which a main draw mechanism with a smaller than usual draw cam and including an auxiliary draw lever adjustable through connections to selvedge stop adjustable lead screw mechanism, is connected to a thread carrier drive bar, and an additional draw mechanism comprises an additional draw cam drive with the main draw cam, a cam follower lever, and means connecting the latter to an additional draw lever which is pivotally mounted on the main draw lever, and wherein the additional draw lever is connected to a slurcam drive bar, so that acceleration and deceleration of the thread carriers and slurcocks are governed by respective draw cams of a composite draw mechanism.

CROSS REFERENCES TO RELATED APPLICATIONS Reference is made to British patent application No. 7,481/69 of Feb. 12, 1969, William Cotton Limited, from which priority is claimed.

This invention is for improvements in or relating to straight bar knitting machines and concerns variable draw mechanism therefor of the type comprising a draw cam, a cam follower lever operable by the draw cam, and draw lever means connected to the cam follower and to the slur bar for reciprocating the slurcams. This type of draw mechanism is usually adapted for also reciprocating thread carriers through the intermediary of a drive bar and frictional connections, the traverse of the thread carriers being limited by selvedge stop adjusting mechanism for fashioning while the drive bar continues its traverse until it is returned with the slur bar by the draw cam. In order to avoid unnecessary travel of the reciprocated parts, the amplitude of movement of the draw lever means is adjustable by means of a lead screw and screw nut device associated with the draw lever means and which is adjusted in synchronism with adjustment of the selvedge stops. Con- .stant lead of thread carriers over slurcocks is automatically obtained. since after the thread carriers have been stopped and the drive bar has continued on, the return of the drive bar immediately carries the thread carrier with it to immediately traverse the thread carriers, whereas since the slurcams have travelled beyond the selvedges, there is a little delay during their return before they act on the selvedge sinkers.

However an undesirable feature has been found in use of this mechanism. Whereas both the slur bar and the thread carrier drive bar have like acceleration and deceleration characteristics from the said draw cam, at the time that the thread carriers are stopped they are travelling at their full velocity, with undesirable consequences.

An object of the invention is to provide draw mechanism of the type referred to of such improved construction as to avoid said undesirable consequences.

The invention provides, in a straight bar knitting machine, draw mechanism comprising a first draw mechanism including a first draw cam and connected to at least one Patented Nov. 30, 1971 thread carrier, at second draw mechanism including a second draw cam and connected to at least one slurcam, and means operably interconnecting the first and second draw mechanisms to provide for required acceleration and deceleration of the thread carrier and slurcam to be obtained from the first draw cam and the second draw cam respectively. Conveniently the first draw mechanism includes a main draw cam, main draw lever means operable by the main draw cam, means for connecting the main draw lever means, including frictionally, to thread carriers, and means for variably adjusting the main draw lever means under control of selvedge stop adjusting means for controlling stopping of the thread carriers, and the second draw mechanism includes an additional draw cam and an additonal draw lever connected to the main draw cam and a main draw lever respectively, and means for connecting the additional draw lever to slurcams. The draw mechanism may have the additional draw lever connected pivotally to the main draw lever and the additional draw cam rotatable with the main draw cam and adapted for imparting to the additional draw lever and the slurcams a greater amplitude of movement than the main draw lever and the thread carriers. The draw mechanism may also have the additional draw cam adapted for the slurcams to be traversed thereby with different amplitudes of traverse to suit different adjustments of the selvedge stop adjusting means respectively, and the main draw cam adapted for the thread carrier drive bar to be traversed with amplitudes less than said different amplitudes respectively. Conveniently the main draw lever means comprises a main draw lever connected to the thread carriers and an auxiliary draw lever connected by adjusting screw and screw nut means to the main draw lever, and having motion transmitting means connected between said adjusting screw and said selvedge stop adjusting means. Conveniently also the connection between the screw and screw nut means of the auxiliary draw lever and the main draw lever is by slide mechanism. There may be a first drive bar to which the main draw lever and the thread carriers are connected, and a second drive bar to which the additional draw lever and the slurcams are connected. Conveniently the main draw cam is of substantially conventional form and the additional cam is of substantially concentric form with rises and falls. Conveniently also the thread carriers are connected to the drive bar by frictional connection means.

The above and other features of the invention set out in the appended claims are incorporated in the constructions which will now be described, as a specific embodiment with reference to the accompanying drawings in which:

FIG. 1 is an elevational view of variable draw mechanism according to the invention in a straight bar knitting machine.

FIG. 2 is a diagrammatic illustration of the draw mechanism.

FIG. 3 is a graph illustrating traverse of slurcocks and thread carriers with acceleration and deceleration characteristics.

FIG. 4 is an enlarged elevational view of the draw mechanism.

FIG. 5 is a cross sectional view of part of the machine showing a draw cam shaft and associated mechanism.

FIG. 6 is a cross sectional view of the machine showing main and additional draw levers of the draw mechanism.

FIG. 7 is a cross sectional view of the machine showing an adjustable lever of the draw mechanism.

FIG. 8 is a cross sectional view of the machine showing adjustable thread carrier selection means in the machine.

Referring to FIGS. 1, 2, 4, the variable draw mechanism has a substantially eccentric main draw cam, in-

dicated at 1, on a cross shaft 2 of a straight bar knitting machine, and this cam operates between two rollers 3, 4 of which the roller 3 is on a cam follower arm 5 pivoted at 6 and the roller 4 is on a cam follower lever 7 pivoted at 8. The two rollers are interconnected by a link 9.

The lower end of the lever 7 is connected by a link 10 to the lower end of a variable draw lever 11 pivoted at 12.

This variable draw lever embodies a lead screw 13 and a screw nut 14, the lead screw 13 being adjustable by control means in synchronism with adjustment of selvedge stops to move the screw nut along the lever. The selvedge stops are indicated at S1, S2 in FIG, 1 and they are mounted on oppositely threaded lead screws L1, L2 which are connected together and are racked round in known manner by known means for adjustment of the selvedge stops for the known purpose of adjusting the amplitude of travel of thread carriers. In the illustrated arrangement one thread carrier bar T1 is secured to the selvedge stop S1 and a second thread carrier bar T2 is secured to the selvedge stop S2. The thread carrier bar T1 has secured to it a stop ST 1 and the thread carrier bar T2 has secured to it a stop 5T2, these stops STl, 8T2 being consequently adjustable towards and away from each other by the known adjustment of the selvedge stops S1 and S2. Thread carriers such as TC are mounted by any suitable friction means on a carrier rod CR which is reciprocated, by draw mechanism to be hereinafter described, to carry the thread carrier along the needle bar NB, the arrangement being such that the traverse of the carrier rod is with a maximum constant amplitude of movement and the traverse of the thread carrier TC by the carrier rod CR is adjustably limited by the adjustment of the stops STl, 8T2 as allowed by the frictional connection between the thread carrier TC and the carrier rod CR.

The said screw nut 14, FIGS. 1 and 4, is slidable along a vertical guideway 15a in a member 15 which is horizontally displaceable by being attached to horizontal bars 16, 17 which are horizontally slidable in guide brackets 18 to 21.

The member 15 is connected by link 22 to a main draw lever 23 which is pivoted at 24 and is connected by a slipper 25 to a driving bar 25a for traverse of thread carriers such as TC FIG. 1 through the intermediary of a selection mechanism SM of known fabric and which is operable in known manner to selectively couple the driving bar 25a to any one of a plurality of thread carrier rods such as CR.

Additional draw mechanism is provided comprising an additional cam 26, FIGS. 1, 2, 4 on the cam shaft 2, cam follower rollers 27, 27a on levers 28, 28a which are interconnected by a link 28b and are operable by the cam, and a link 29 connecting the lever 28a to an additional draw lever 30.

The addtional cam 26 is basically eccentric and has opposed rise and fall portions 26a, 26b which are disposed to act on the cam follower roller 27 when the main draw cam is approaching its two limits of cam motions respectively.

The additional draw lever 30 is pivotally connected to the main draw lever 23 at 31, and its upper end is connected through a releasable catch device 30:: to the slur bar SB FIG. 1 to which the slur cams SC are secured.

The effect of this additional mechanism is that the main draw lever 23, during its motion to traverse the thread carrier driving bar 25a, carries with it the additional draw lever 30 to traverse the slur bar SB. Towards each end of the motion of the main draw lever 23, the additional draw lever is caused by the rise 26a and fall 26b of the additional cam 26 to gain on the main draw lever 23 until it has carried the slur earns a required distance further.

Since the additional draw lever 30 is pivotally connected to the main draw lever 23 it not only moves with it by the main draw cant I but it is subjected to the same adjustments by the variably adjustable lever 11. Consequently in all end positions of the main draw lever 23, the auxiliary draw lever 30 has extra motions imparted to it which are of substantially constant amplitude. It will be also understood that since the terminal motions of the two draw levers are determined by the two draw cams respectively, the slur cams have acceleration and deceleration characteristics determined by the additional draw cam, and the thread carriers have acceleration and deceleration characteristics determined by the main draw cams i.e. in the approaches of the thread carrier to the stops ST ST This is illustrated in FIG. 3 from which it will be seen that at about the same stage near one end of the draw, the draw being represented by the straight plotted line A for the slur cams and B for the thread carriers, the plotted lines change between straight and curved portions A B and whereas the curve A is comparatively shallow representing acceleration and deceleration of slurcams from and to their final position at A, the curve B is of less radius representing acceleration and deceleration of the thread carrier rod or driving bar from and to its final position at B The position C is that at which the thread carriers are stopped by the stops.

It will be understood that similar conditions arise at the other end of the draw.

The plotted lines A, A A B, B B and position C represent conditions for Wide fabric, but it will be seen that for narrow fabric, plotted lines D, D D E, E, E and position C prove that substantially similar characteristics occur irrespective of the width of fabric produced, the curve D being of opposite form to that of the curve E instead of being of the form of curve A It will be also appreciated from FIG. 3, that the carrier rod or driving bar, although having a greater traversing movement than the thread carriers, does not traverse to the same extent as the slur cams. Since the shorter traverse of the carrier rod or driving bar is obtained by the main draw cam, and in usual practice the carrier rod or driving bar and the slur cams are traversed to the same greater extent by the one main draw lever, it follows that the main draw cam in the present instance is advantageously of less diameter than the usual main draw cam.

The mechanical construction and arrangement of the additional mechanism is designed to suit a particular machine. In the example shown in FIGS. 1 and 6, the slipper 25 for the main draw lever 23 is shown on a guide bar 32 and connected by a short bracket 25b to the driving bar 2511. The additional draw lever is composed of two parts 30b, 30c interconnected in cranked form to be clear of existing parts in the machine. The upper end of the auxiliary draw lever 30 is shown connected to a slipper 33 which is on a guide rod 34 and is connected to the slur bar 35 for the slurcams SC and a pivoted arm 30d gives added support for the draw levers.

FIG. 5 shows that the cross shaft 2 is driven from the usual main cam shaft MCS through gearing G, and it also shows that the draw cams 1, 26 and associated levers 7, 28a are in comparatively close relationship axially of the shaft 2.

FIGS. 1 and 7 also show that the draw lever adjusting screw 13 is adjusted in known manner by the selvedge stop lead screws L, L through drive transmitting means DTS.

FIG. 8 shows a cross sectional view of the selvedge stop lead screw L part of the drive transmitting means DTS, the selection means SM, and a plurality of the carrier rods CR, the selection means SM being adapted in known manner to be adjusted with the selvedge stops S2 and to be releasably coupled to any one of the carrier rods CR.

It is to be understood that the mechanism may be modified to some extent without departing from the concept of the invention. For example it is conceivable that the main draw cam or eccentric could be arranged to drive the slurcocks, and the auxiliary draw cam could be designed to provide for the traverse of the thread carriers being with the required less amplitude.

What we claim is:

1. In a straight bar knitting machine, the combination of first draw mechanism comprising a main draw cam, main draw lever means operable by the main draw cam, means for connecting the main draw lever means, including frictionally, to thread carriers, and means for variably adjusting the main draw lever means under control of selvedge stop adjusting means for controlling stopping of the thread carriers, second draw mechanism comprising an additional draw cam and an additional draw lever connected to the main draw cam and the main draw lever means respectively, and means for connecting the additional draw lever to slurcams, to provide for required acceleration and deceleration of the thread carrier and slurcam to be obtained from the first draw cam and the second draw cam respectively.

2. Draw mechanism according to claim 1 having the additional draw lever connected pivotally to the main draw lever means, and the additional draw cam rotatable with the main draw cam and adapted for imparting to the additional draw lever and the slurcams a greater amplitude of movement than the main draw lever means and the thread carriers.

3. Draw mechanism according to claim 1 having the additional draw cam adapted for the slurcams to be traversed thereby with different maximum amplitudes of traverse to suit different adjustments of the selvedge stop adjusting means respectively, and the main draw cam adapted for the thread carriers to be traversed with amplitudes less than said maximum amplitudes respectively.

4. Draw mechanism according to claim 1 wherein the main draw lever means comprises a main draw lever connected to the thread carriers and an auxiliary draw lever connected by adjusting screw and screw nut means to the main draw lever motion transmitting means are connected between said adjusting screw and said selvedge stop adjusting means.

5. Draw mechanism according to claim .1 wherein the main draw lever means comprises a main draw lever connected to the thread carriers and an auxiliary draw lever connected by adjusting screw and screw nut means to the main draw lever, motion transmitting means are connected between said adjusting screw and said selvedge stop adjusting means, and connection between the screw and screw nut means of the auxiliary draw lever and the main draw lever is by slide mechanism.

6. Draw mechanism according to claim 1 having a first drive bar to which the main draw lever and the thread carriers are connected, a second drive bar to which the additional draw lever and the slurcams are connected.

7. Draw mechanism according to claim 1 wherein the main draw cam is of substantially conventional form and the additional cam is of substantially concentric form with rises and falls.

8. Draw mechanism according to claim 1 having a first drive bar to which the main draw lever and the thread carriers are connected, a second drive bar to which the additional draw lever and the slurcams are connected, and the thread carriers connected to the first drive bar by frictional connection means.

References Cited UNITED STATES PATENTS 1,235,185 7/1917 Cecka 66130 1,719,839 7/1929 Hilscher 66-130 2,022,468 11/1935 Hug 66-126 2,872,798 2/1959 Matthews -126 X RONALD FELDBAUM, Primary Examiner 

